While electric brakes and the like have been utilized in connection with certain textile carding and drafting apparatus such as illustrated in U.S. Pat. No. 3,530,542 such have proved to be impractical insofar as providing an instantaneous stop. Efforts to utilize electric brakes such as illustrated in the patent have proved to be impractical to create an instantaneous stop and are not serviceable over a long period of time. This is because by their nature they are concentrically mounted and a minimum of lever arm is afforded in order to create stopping torque.
An important advantage of an instantaneous stop is to make it possible to stop the various carding elements associated with or driven by the main cylinder quickly and in proportion so as not to cause the web to come down but rather to remain up so that carding may be resumed quickly. It would thus be possible to stop the card without having to put up the web each time when starting again. This would be of special advantage in stops over the weekend where the card may simply be restarted without having to put the ends up at the beginning of the week.
The instantaneous stopping apparatus is especially desirable for the use when conducting maintenance operations. During maintenance operations the card is blown down or cleaned by blasts of air in which case it is necessary to move the covers and perhaps the cleanout doors at the bottom of the frame. When clearing chokes, it is important that the main cylinder be stopped. This normally takes about ten minutes and operators have the tendency to become impatient and may not realize that the main cylinder is still rotating. Switches for actuating the braking mechanism of the invention may be placed in a number of locations such as on the doors and covers, as well as on the regular panel for the electrical circuitry. It is important that the braking mechanism be carried adjacent the main cylinder shaft on the side of the card.
It has been found to be important in such a system to drive the doffer and associated components as shown directly coupled to the main cylinder to provide a substantially simultaneous stopping of such components avoiding irregularities in the web as well as preventing the web from coming down.